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for forming self-assembled, micellar structures, [2] these polymers are also increasingly employed for advanced technologies such as drug-delivery and tissue engineering, [3][4][5][6][7] or as structure-directing agents for the preparation of mesoporous materials. [8][9][10] For medical applications specifically, Pluronic-type polyethers are of interest because of their a) commercial availability in a variety of different molecular weights and EO/PO ratios, b) biocompatibility and non-toxic properties, and c) ability to form hydrogels. [11] For the latter, the reverse thermo-responsive behavior of these amphiphilic polyethers is exploited. Thus, at room temperature, aqueous solutions typically display a low viscosity, while an increase of temperature yields rapid gelation. If parameters are chosen correctly, syringe-injectable systems can thus be realized, which swiftly gel at body temperature. [4] In principle, the gels can then be used to continuously release drugs or to serve as scaffolds for cell-growth. [11] Unfortunately, however, hydrogels derived from these triblock copolymers show only limited stability and require relatively high polyether loadings of >15 wt%; the material is highly permeable, erodes quickly, and is overall mechanically weak. [12,13] This represents a major disadvantage for employment in biomedicine, and consequently, significant research effort has been devoted to work around this problem. Approaches include the chemical modification and/or chemical cross-linking of Pluronics, [14][15][16][17] chain extension to form multiblock poly(ethylene oxide)poly(propylene oxide) (PEO-PPO) polymers, [18,19] or the generation of blends with other polymers. [20][21][22][23] Epoxides with longer alkyl side chains have also been employed for a similar purpose. [24] In general, the development of strategies to enhance the mechanical robustness of hydrogels is an intensely studied field of research. [25] For this contribution, a simpler strategy was envisioned which actually leaves the typical constitution of Pluronics intact but exploits the thermodynamics of micellization to result in more robust hydrogels. Thus, first, based on the finding that the polyether molar mass clearly scales with the viscosity/ storage modulus of the corresponding hydrogel, [18] PEO-PPO copolymers with exceptionally high molecular weights were targeted, well beyond the scope of commercial availability (up to 13 000 g mol −1 for F127 or F98). This was enabled by recent progress in polymerization catalysis, [26,27] which makes Hydrogels based on Pluronics (EO n/2 -PO m -EO n/2 , EO = ethylene oxide, PO = propylene oxide) have been frequently investigated, yet key limitations still remain, including a propensity for quick erosion and insufficient mechanical robustness. This issue can be alleviated by creating "reverse Pluronics" (PO n/2 -EO m -PO n/2 ), which is proposed to enable the formation of physical cross-links via a micellar network. Until recently, however, efforts in this direction were aggravated by synthetic diffic...

Using an organocatalytic polymerization method for the preparation of well-defined, amphiphilic block copolyethers of the type PPO n/2 -PEO m -PPO n/2 ("Reverse Pluronics", M n up to 50 000 g/mol, Đ M = 1.01−1.08, >100 examples), it is demonstrated that the application of these polymers as structure-directing agents (SDAs) in a standard softtemplating process delivers ordered mesoporous carbons (OMCs), whereby the resulting pore diameters are monomodal and narrowly distributed. Moreover, by the judicious choice of the SDA properties (total molar mass, ratio of n and m, and PPO block length), pore diameters in the range of 6−18 nm can be selectively addressed, notably within the same arrangement pattern (2D hexagonal, p6mm). This provides a rational, operationally simple method to tailor pore properties of otherwise uniform carbons, also significantly reducing the effort necessary to obtain systematically altered materials. Ready access to such quick screenings is assumed to be immensely useful for pore size-dependent applications from numerous disciplines such as sensing, catalysis, or energy storage and conversion. Surprisingly, it is not only found that a minimum of M n = 13 000 g/mol is required to deliver ordered (nondistorted) materials under these conditions but also that very high-molar-mass SDAs are best suited to achieve optimum results, potentially providing an explanation for why "Reverse Pluronics" are frequently, and wrongly, thought to be per se unsuitable for the preparation of well-ordered mesoporous carbons.